2. Regulations. Developments

2.1 First documents

• DTU 20 (January 1961)

  This unified technical document (DTU), which deals with walls and partitions made of small masonry units, simply refers to stapled thin stones with an air gap as "type 3 walls not conforming to this DTU".

  At the time, there were no regulations governing these relatively new techniques, and the only applicable rules were the professional rules of the marble masons.

• Securitas recommendations (November 1972)

  These recommendations were made necessary by the appearance of numerous disorders, in particular those caused by the compression of the stones.

  This document introduces the concept...